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Trending Lyricist I
June 10, 2020

LG C9 and Sonos Arc

Hey all, my Arc was delivered this morning and I've had a chance to hook it up to my LG C9 directly via eARC and ran a few tests regarding Atmos and other features.

Built in apps:

  • Netflix - Reporting Dolby Atmos (DD+) for Atmos content.

  • Disney+ - Reporting Dolby Digital Plus 5.1 (though this is likely due to the current throttling taking place in the EU)

  • Amazon Prime - Reporting Dolby Atmos (DD+) for Atmos content.

Xbox One:

  • HDMI Audio set to Bitstream out and Bistream Format set to Dolby Atmos has no delay, finally! Displays Dolby Atmos in Sonos app.

PS4:

  • Like with the Xbox, there's no delay on Bitstream HDMI audio

NVidia Shield Pro:

  • Netflix - Reporting Dolby Atmos (DD+) for Atmos content.

  • Amazon Prime - Reporting Dolby Atmos (DD+) for Atmos content.

  • Disney+ - Reporting Dolby Digital Plus 5.1 (though this is likely due to the current throttling taking place in the EU). After connecting up to a US VPN it's reporting Dolby Atmos (DD+) for Atmos content.

  • PLEX - This is where it gets slightly annoying. Playing TrueHD content it reports Stereo 2.0. Setting Passthrough to HDMI reports Dolby Atmos (TrueHD). For DTS content you need to switch the Passthrough setting to Optical which in turn causes TrueHD to playback in Dolby Digital Plus 5.1.

Apple TV:

  • iTunes Content - Reports Dolby Atmos for Atmos content. Non Atmos content reports Stereo 2.0. With Change Format > On and New Format > Dolby Digital 5.1, I receive Dolby Digital 5.1 from non-Atmos iTunes content. I ran this test using Beetlejuice and Avengers Assemble.

  • Netflix - Reports Dolby Atmos for Atmos content.

  • Amazon Prime - Reports Dolby Atmos for Atmos content.

  • Disney+ - Reporting Stereo 2.0 for all content bizarrely. Setting audio output on the Apple TV to Dolby 5.1 allows all content to playback in 5.1 rather than stereo.

My C9 is running firmware 04.80.03 with the following settings:

Sound Out

HDMI ARC selected

Digital Sound Out set to Passthrough

eARC set to ON

Additional Settings

DTV Audio Setting set to Auto

HDMI Input Audio Format set to Bitstream.

 

If there's anything else I can test or any questions, let me know!

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134 replies

ZophopAuthor
Trending Lyricist I
June 10, 2020

I've go an lg b9 and when I play something that is Atmos it shows on the tv as playing Dolby vision and then in the sonos app it shows dd+ I don't think that is Dolby Atmos is it?. If I unplug the arc and play the same Netflix prog through the tv speakers it says Dolby vision and underneath Dolby atmos

Looks like I’m having the same problem, as I own an LG B9 TV too , difference is I saw the “vision and atoms” sign near to the movie title once and then it didn’t show in other movies, back again to the same movie it’s no longer there. the app also doesn’t read atoms , reads Dolby digital 5.1 

 

any recommendations? 
 

Thanks 

Actually I’ve just realized that the vision.atmos sign was only when the arc is off ! 

Hey! Have you tried recreating Bezzer’s steps in this post? 

Lyricist I
June 10, 2020

Have you tried the PLEX app from LG content store?

Ryan S
Retired Sonos Staff
June 10, 2020

C9 / Apple TV / Arc

 

Atmos working on Netflix, but all other 5.1 just shows as stereo 2.0 on Sonos app.

 

ATV change format off, atmos on

C9 eARC enabled. Digital sound out is Auto.

if I set sound out to pass through I get what appears to be two non speech channels passed to Sonos. Very odd.

 

 

The two channel non-speech is what would happen if a multichannel L-PCM signal is sent to Arc. Only the left and right channels are being played, since only stereo PCM is supported right now. The team just started looking into adding L-PCM to Arc for the future,  based on community request, but we haven’t released a timeline for that yet. 

You’ll want to have your source outputting Dolby Digital or PCM Stereo to avoid missing things like dialogue.

Mark good posts by pressing the like button, and select the best answer on questions you've asked to help others find solutions.
ZophopAuthor
Trending Lyricist I
June 10, 2020

Have you tried the PLEX app from LG content store?

Using the WebOS Plex app when playing TrueHD content only outputs as Dolby Digital 5.1 sadly.

ZophopAuthor
Trending Lyricist I
June 10, 2020

C9 / Apple TV / Arc

 

Atmos working on Netflix, but all other 5.1 just shows as stereo 2.0 on Sonos app.

 

ATV change format off, atmos on

C9 eARC enabled. Digital sound out is Auto.

if I set sound out to pass through I get what appears to be two non speech channels passed to Sonos. Very odd.

 

 

The two channel non-speech is what would happen if a multichannel L-PCM signal is sent to Arc. Only the left and right channels are being played, since only stereo PCM is supported right now. The team just started looking into adding L-PCM to Arc for the future,  based on community request, but we haven’t released a timeline for that yet. 

You’ll want to have your source outputting Dolby Digital or PCM Stereo to avoid missing things like dialogue.

Hey Ryan, thanks for that! Sounds like it was really unlucky timing with LG releasing the LPCM passthrough firmware just as the Arc releases. I’m looking forward to the LPCM functionality in the future as it seems like that’ll solve all the weird quirks with the Apple TV and my lovely new Arc.

Enthusiast II
June 10, 2020

C9 / Apple TV / Arc

 

Atmos working on Netflix, but all other 5.1 just shows as stereo 2.0 on Sonos app.

 

ATV change format off, atmos on

C9 eARC enabled. Digital sound out is Auto.

if I set sound out to pass through I get what appears to be two non speech channels passed to Sonos. Very odd.

 

 

The two channel non-speech is what would happen if a multichannel L-PCM signal is sent to Arc. Only the left and right channels are being played, since only stereo PCM is supported right now. The team just started looking into adding L-PCM to Arc for the future,  based on community request, but we haven’t released a timeline for that yet. 

You’ll want to have your source outputting Dolby Digital or PCM Stereo to avoid missing things like dialogue.

Hey Ryan, thanks for that! Sounds like it was really unlucky timing with LG releasing the LPCM passthrough firmware just as the Arc releases. I’m looking forward to the LPCM functionality in the future as it seems like that’ll solve all the weird quirks with the Apple TV and my lovely new Arc.

Haven’t unpacked my C9 yet as it only arrived today. I hope the LPMC update for the Arc happens sooner rather than later as I usually prefer to use my ATV than inbuild apps. 

Lyricist II
June 10, 2020

I’ve set eARC off on the LG B9 TV, and started receiving Dolby atmos perfectly !

Lyricist III
June 11, 2020

C9 / Apple TV / Arc

 

Atmos working on Netflix, but all other 5.1 just shows as stereo 2.0 on Sonos app.

 

ATV change format off, atmos on

C9 eARC enabled. Digital sound out is Auto.

if I set sound out to pass through I get what appears to be two non speech channels passed to Sonos. Very odd.

 

 

What firmware version is your C9?


Currently running 04.80.03

ZophopAuthor
Trending Lyricist I
June 11, 2020

Having done some more testing, the issue with Apple TV content outputting as Stereo definitely appears to be due to the newest LG C9 firmware for LPCM. I’d advise not upgrading to 04.80.03 if your main media device is the Apple TV until Sonos patch in LPCM for the Arc.

Local Superstar
June 11, 2020

I've go an lg b9 and when I play something that is Atmos it shows on the tv as playing Dolby vision and then in the sonos app it shows dd+ I don't think that is Dolby Atmos is it?. If I unplug the arc and play the same Netflix prog through the tv speakers it says Dolby vision and underneath Dolby atmos

Looks like I’m having the same problem, as I own an LG B9 TV too , difference is I saw the “vision and atoms” sign near to the movie title once and then it didn’t show in other movies, back again to the same movie it’s no longer there. the app also doesn’t read atoms , reads Dolby digital 5.1 

 

any recommendations? 
 

Thanks 

Actually I’ve just realized that the vision.atmos sign was only when the arc is off ! 

Hey! Have you tried recreating Bezzer’s steps in this post? 

What @Bezzer  is seeing is correct.

If I watch Atmos content from builtin Nextflix App on my LG Series 8 OLED using INTERNAL TV  speakers I see ‘Dolby Vision’ AND ‘Dolby ATMOS’ logo top right.

If I watch Atmos content from builtin Nextflix App on my LG Series 8 OLED using Sonos Arc speakers connected via ARC (no eARC on series 😎 I see only see ‘Dolby Vision’ logo on TV. BUT I see Dolby Atmos logo on the Sonos App.

My assumption is the LG TV knows its playing Atmos if its via internal speakers, hence it displays the logo. If its passing sound to an external decoder, the TV doesn’t know how its being decoded, so cant display the Atmos logo, even if it is being decoded correctly as Atmos.